The broad long-term goal of this project is to develop a better understanding of the sequence and underlying physiological processes of speech/voice development of children with hearing loss (HL). Knowing the strategies that children with HL use as they develop oral communication and how these strategies may impact on their future abilities to produce acceptable speech and voice may reveal particularly maladaptive behaviors for which early intervention would be beneficial. It also may assist in the development of treatments that address the underlying pathophysiology contributing to deviant speech/voice production of children with HL. Specific aims of the project are: 1) to compare speech/voice development of children with varying degrees of HL and different types of sensory aids; 2) to determine if exaggerated and/or excessively tensed speech/voice behaviors occur for children with HL and if these behaviors co-occur with deviant articulatory patterns; 3) to compare the effects of subglottal pressure magnitude on articulatory and phonatory behaviors of children with and without HL; 4) to compare the effectiveness of two strategies for treating deviant articulatory behaviors of children with HL. Perceptual, acoustic and physiologic analyses will be used to assess specific articulatory and phonatory behaviors. Cross-sectional and experimental data will be collected from children with normal hearing, severe HL, and profound HL. Longitudinal data of deaf children who use hearing aids will be compared to data obtained from children who use cochlear implants. A single-subject design will compare the effectiveness of two approaches for treating negative intraoral pressures of children with HL, one that addresses the primary pathophysiology and one that addresses the secondary symptom. Results of this work should be helpful in developing new methods of diagnosis and treatment of the oral communication problems of children with HL and in determining treatment efficacy.